Field of the Invention
The present invention relates to golf balls.
Specifically, the present invention relates to so-called two-piece golf balls including a core and a cover.
Description of the Related Art
Upon an accurate shot, a golf ball is hit at the sweet spot of a clubface. The shock generated by this shot is small. Upon a mishit, a golf ball is hit at a portion of a clubface other than the sweet spot. The shock upon the mishit is large. The large shock gives pain to the golf player. At this time, the golf player feels discomfort. Particularly, upon a mishit made when the temperature is low (for example, in winter), a golf player feels a sharp pain.
Golf players generally desire golf balls having favorable feel at impact. Particularly, beginners prefer soft feel at impact. This is because the frequency of a mishit is high in play by beginners.
So-called thread-wound balls used to be mainstream golf balls. At present, thread-wound balls are almost not available commercially. In recent golf, two-piece balls, three-piece balls, four-piece balls, five-piece balls, six-piece balls, and the like are used.
A two-piece ball includes a core and a cover. The structure of the two-piece ball is simple. The two-piece ball can be manufactured at low cost. A proposal concerning two-piece balls is disclosed in JPH5-123422 (U.S. Pat. No. 5,304,608).
Upon shots by beginners, golf balls often fly in an unintended direction. Golf balls often fall into a pond or fly into woods. Beginners often loose golf balls. Therefore, beginners do not prefer expensive golf balls. Two-piece balls are suitable for beginners, since two-piece balls can be manufactured at low cost. As descried above, beginners prefer soft feel at impact. Improvement of feel at impact of two-piece balls is desired.
With a two-piece ball in which a core having a large amount of deformation upon hitting is adopted, soft feel at impact can be achieved. However, in this golf ball, a cover thereof cannot follow deformation of the core. Large deformation of the core causes breakage of the cover. The durability of the two-piece ball in which this core is adopted is not good.
An object of the present invention is to provide a two-piece golf ball having excellent feel at impact and excellent durability.